Tube or Solid State?

Which is generally considered a cleaner sound? I always thought tube amps generally gave a cleaner, fatter sound and SS amps could make better distortion. Is this correct? thanks. (I've got an Eden Metro and don't know which side to play out of...)

Well, I've always thought that the SS amps have a cleaner sound. Tube amps have a "distortion" sound when you drive them hard, that some players like. (I personally don't like the clipping sound of a tube amp myself)

I've got answers for both questions!
Tube amps will sound just as clean as SS amps when both are being operated in their linear range (ie no clipping anywhere in the chain). Maybe cleaner..... When tube amps are being overdriven they sound better than SS amps being overdriven. Whether you like an overdriven tube amp's sound better than a clean SS amp's sound is purely a matter of taste. This wil also vary from amp to amp.

2) tube amps put out the same power at different impedences because the actual power amp is coupled to a transformer and doesn't go directly the output. So the amp sees the same impedence no matter what the impedence of the speaker is. The transformer will have several secondary windings to match several impedences. These secondary windings are connected to the speaker out jacks. you can usually change which windings you use with an impedence switch. The caveat here is that you should only use speaker combinations with impedences that match those of the transformer. So if you have an amp with a switch that switches between 4 and 8 Ohms, those are the only loads you should use with that amp.

In that situation, there probably wouldn't be much harm in using the 2 or 4 Ohm tap. There'd be a mismatch, but probably not enough to cause any trouble. I ran an 8 Ohm box off an SVT for a while, and those only do 2 or 4 ohms.....I got nervous about it though. To be absolutely safe I got a 4 Ohm box.....

As for your second question....if only it was that simple...
There are a lot of factors that this depends on. Let's just simplify a little. Suppose we have an amp with only one volume knob, instead of gain and master volume. The amount of signal that's coming out of your bass determines where that volume knob will be for full power. If you play really light, you'll have to turn that knob up more to get full power than if you play really hard (assuming same bass and settings). The knob basically adjusts the sensitivity of the amp to the signal from your bass. So there's no actual setting that is always 100W or whatever. It depends. Now for the gain and master thing. The gain is just the sensitivity of the amp's input to the signal from the bass. The master volume is just the sensitivity of the power section of the amp to the signal from the preamp section. This makes both infinitely adjustable and able to handle many different levels of signal. There's enough gain built in that if both knobs are on ten, even the weakest of signals from a bass can drive the amp well beyond it's linear limits, resulting in distortion. Actually, when the amp's distorting (power amp, not the same as a distortion pedal) it actually produces more than its rated power. The rated power is measured at some small percentage of harmonic distortion, by the time you can actually hear distortion the percentage is quite high.

Originally posted by lpbassics so... how do they justify rating an amp at any specific wattage?

here's my take [at least with what i can try to understand]

if a ss amp is rated at 100 watts, it will amplify up to that level and then start clipping.

tube? it goes up to a 100 watts and then continues upward only distorting.

does that sound kinda right?

thx a lot,
lp

Click to expand...

Well, clipping and distortion amount to the same thing. distortion is the "sound" of clipping. Also, a 100W tube and and a 100W SS amp (assuming that they were rated using the same test criteria, which isn't always the case) will start to clip at the same wattage and the progression into more and more distortion is at the same rate. Why to tube amps sound good when overdriven? Harmonics. Overdriven tubes produce a lot of even order harmonics which sound musical to us, while SS amps produce a lot of odd order harmonics which sound harsh. So a tube amp and an SS amp will sound radically different at the same percentage of total harmonic distortion (THD). In fact, a tube amp won't even sound like it is distorting until there is quite a high THD. It will sound more like a slight compression. Some people like this, some don't. I do, that's why I own a '76 SVT......

There are other factors at play here as well but it can get pretty complex.....
hope this helps....

Please don't confuse TONE with "clean" or dirty or brittle etc. Those definitions are usually thought of when speaking of tones. My all tube amp is very clean meaning it's quiet and consistant. I can dial in many different flavors such as grit etc. Tube amps do have a warmer sound than solid state or hybrid amps (tube pre section). It's all what you like. Let your ears decide. There are many different ways to make your all tube amp sound too. Usually by changing to the tube of choice both power or pre side or both. Just my humble opinion.